| 1 | /* Optimized string comparison. |
| 2 | Copyright (C) 2001-2002, 2007, 2009-2020 Free Software Foundation, Inc. |
| 3 | |
| 4 | This program is free software: you can redistribute it and/or modify it |
| 5 | under the terms of the GNU General Public License as published |
| 6 | by the Free Software Foundation; either version 3 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| 16 | |
| 17 | /* Written by Bruno Haible <bruno@clisp.org>. */ |
| 18 | |
| 19 | #ifndef _GL_STREQ_H |
| 20 | #define _GL_STREQ_H |
| 21 | |
| 22 | #include <string.h> |
| 23 | |
| 24 | /* STREQ_OPT allows to optimize string comparison with a small literal string. |
| 25 | STREQ_OPT (s, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0) |
| 26 | is semantically equivalent to |
| 27 | strcmp (s, "EUC-KR") == 0 |
| 28 | just faster. */ |
| 29 | |
| 30 | /* Help GCC to generate good code for string comparisons with |
| 31 | immediate strings. */ |
| 32 | #if defined (__GNUC__) && defined (__OPTIMIZE__) |
| 33 | |
| 34 | static inline int |
| 35 | streq9 (const char *s1, const char *s2) |
| 36 | { |
| 37 | return strcmp (s1 + 9, s2 + 9) == 0; |
| 38 | } |
| 39 | |
| 40 | static inline int |
| 41 | streq8 (const char *s1, const char *s2, char s28) |
| 42 | { |
| 43 | if (s1[8] == s28) |
| 44 | { |
| 45 | if (s28 == 0) |
| 46 | return 1; |
| 47 | else |
| 48 | return streq9 (s1, s2); |
| 49 | } |
| 50 | else |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | static inline int |
| 55 | streq7 (const char *s1, const char *s2, char s27, char s28) |
| 56 | { |
| 57 | if (s1[7] == s27) |
| 58 | { |
| 59 | if (s27 == 0) |
| 60 | return 1; |
| 61 | else |
| 62 | return streq8 (s1, s2, s28); |
| 63 | } |
| 64 | else |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static inline int |
| 69 | streq6 (const char *s1, const char *s2, char s26, char s27, char s28) |
| 70 | { |
| 71 | if (s1[6] == s26) |
| 72 | { |
| 73 | if (s26 == 0) |
| 74 | return 1; |
| 75 | else |
| 76 | return streq7 (s1, s2, s27, s28); |
| 77 | } |
| 78 | else |
| 79 | return 0; |
| 80 | } |
| 81 | |
| 82 | static inline int |
| 83 | streq5 (const char *s1, const char *s2, char s25, char s26, char s27, char s28) |
| 84 | { |
| 85 | if (s1[5] == s25) |
| 86 | { |
| 87 | if (s25 == 0) |
| 88 | return 1; |
| 89 | else |
| 90 | return streq6 (s1, s2, s26, s27, s28); |
| 91 | } |
| 92 | else |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static inline int |
| 97 | streq4 (const char *s1, const char *s2, char s24, char s25, char s26, char s27, char s28) |
| 98 | { |
| 99 | if (s1[4] == s24) |
| 100 | { |
| 101 | if (s24 == 0) |
| 102 | return 1; |
| 103 | else |
| 104 | return streq5 (s1, s2, s25, s26, s27, s28); |
| 105 | } |
| 106 | else |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static inline int |
| 111 | streq3 (const char *s1, const char *s2, char s23, char s24, char s25, char s26, char s27, char s28) |
| 112 | { |
| 113 | if (s1[3] == s23) |
| 114 | { |
| 115 | if (s23 == 0) |
| 116 | return 1; |
| 117 | else |
| 118 | return streq4 (s1, s2, s24, s25, s26, s27, s28); |
| 119 | } |
| 120 | else |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static inline int |
| 125 | streq2 (const char *s1, const char *s2, char s22, char s23, char s24, char s25, char s26, char s27, char s28) |
| 126 | { |
| 127 | if (s1[2] == s22) |
| 128 | { |
| 129 | if (s22 == 0) |
| 130 | return 1; |
| 131 | else |
| 132 | return streq3 (s1, s2, s23, s24, s25, s26, s27, s28); |
| 133 | } |
| 134 | else |
| 135 | return 0; |
| 136 | } |
| 137 | |
| 138 | static inline int |
| 139 | streq1 (const char *s1, const char *s2, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28) |
| 140 | { |
| 141 | if (s1[1] == s21) |
| 142 | { |
| 143 | if (s21 == 0) |
| 144 | return 1; |
| 145 | else |
| 146 | return streq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28); |
| 147 | } |
| 148 | else |
| 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | static inline int |
| 153 | streq0 (const char *s1, const char *s2, char s20, char s21, char s22, char s23, char s24, char s25, char s26, char s27, char s28) |
| 154 | { |
| 155 | if (s1[0] == s20) |
| 156 | { |
| 157 | if (s20 == 0) |
| 158 | return 1; |
| 159 | else |
| 160 | return streq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28); |
| 161 | } |
| 162 | else |
| 163 | return 0; |
| 164 | } |
| 165 | |
| 166 | #define STREQ_OPT(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \ |
| 167 | streq0 (s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28) |
| 168 | |
| 169 | #else |
| 170 | |
| 171 | #define STREQ_OPT(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \ |
| 172 | (strcmp (s1, s2) == 0) |
| 173 | |
| 174 | #endif |
| 175 | |
| 176 | #endif /* _GL_STREQ_H */ |